• Journal of Preventive Medicine and Public Health
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• v.35 no.4
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• pp.269-274
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• 2002

Objectives : To evaluate the elect of glutathione(GSH) on lead induced modulation of nitric oxide(NO) synthesis, and to examine how lead modulates NO production in macrophages. Methods : This study was observed in a culture of RAW 264.7 cells, which originated from a tumor in a Balb/c mouse that was induced by the Abelson murine leukemia virus. The compounds investigated were lead chloride, N-acetyl-cystein(NAC), and Buthionine Sulfoximine( BSO). Results : ATP synthesis in RAW 264.7 cells was unchanged by each lead concentration exposure in a dose dependent manner. The NO synthesis was decreased when exposed to lead($PbCl_2$) concentration $0.5{\mu}M$. The presence of $300{\mu}M$ NAC, used as a pretreatment in the culture medium, caused the recovery of the lead induced decrease in NO synthesis, but in the presence of $300{\mu}M$ BSO as a pretreatment, there was no recoverey. Pretreatment with NAC and BSO had no affect on ATP synthesis at any of the lead concentrations used. Conclusions : These results indicated that GSH has a protective effect toward lead toxicity, and suggested that the inhibition of NO production in macrophage due to lead toxicity may be related to cofactors of iNOS (inducible nitric oxide synthase)

• Journal of Periodontal and Implant Science
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• v.35 no.4
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• pp.1081-1095
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• 2005

본 연구는 치주질환 주요 병인균주 중의 하나인 Porphyromonas gingivalis의 세균내독소가 마우스 대식 세포주인 RAW264.7 세포에서의 nitric oxide의 생성과 iNOS의 발현에 미치는 영향을 분석하고 그 기전을 규명하기 위해 수행되었다. Butanol추출법과 phenol-water법에 의해 P. gingivalis 381로부터 세균내독소를 추출하였으며, NO의 생성은 배양 상층액 내의 nitrite 농도를 측정하여 결정하였다. 또한, iNOS의 western blot 분석과 reverse transcription (RT)-PCR 산물의 분석을 수행하였다. P. gingivalis의 세균내독소는 부가적인 자극이 없는 상태에서도 iNOS의 발현과 NO 생성을 유발하였으며, NF- ${\kappa}B$, microtubule polymerization, protein tyrosine kinase, 그리고 protein kinase C 등이 P. gingivalis 세균내독소에 의한 NO 생성에 간여하는 것으로 여겨진다. 또한, P. gingivalis 세균내독소에 의한 NO 생성에는 L-arginine이 요구되었다. P. gingivalis 세균내독소에 의한 NO 생성은 염증성 치주질환의 발병과 진행에 있어 중요한 역할을 하는 것으로 여겨진다.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.511-515
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• 2014

In a screen for plant-derived inhibitors of nitric oxide (NO) production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophage cells, a flavonol isolated from the chloroform extract of Alpinia officinarum was isolated. The structure of the flavonol was found to be 3,5,7-trihydroxy-2-phenylchromen-4-one (galangin, GLG) by using spectroscopy. GLG exhibited an inhibitory effect ($IC_{50}$ value: $26.8{\mu}M$) on NO production in LPS-stimulated RAW 264.7 murine macrophage cells. Moreover, GLG suppressed expressions of inducible nitric oxide synthase (iNOS) protein and mRNA in a dose-dependent manner.

• Food Science of Animal Resources
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• v.21 no.4
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• pp.374-382
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• 2001

Lactoferrin(Lf) has the function of modulation in the host defense systems, including cytokine production and immune responses. We have tested the effect of Lf and Lf ydrolysates(Lf-H) on the productions of tumor necrosis factor-${\alpha}$(TNF-${\alpha}$) and nitric oxide(NO) in macrophage cells. Lf from Korean native cattle(K-Lf) and hydrolyzed K-Lf(K-Lf-H) increased the production of TNF-${\alpha}$ in RAW264.7 cells with dose-dependency. Bovine Lf(B-Lf), human Lf(H-Lf), and its hydrolysates did not induce either TNF-${\alpha}$ production or NO production. On the other hand those didn\`t affect on the production of TNF-${\alpha}$ in lipopolysaccharide(LPS)-stimulated RAW264.7 cells. K-Lf induced the production of NO similar to its role on the TNF-${\alpha}$ production.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.1
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• pp.190-199
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• 1993

In order to find the effect of flame interaction on NO production, dual laminar diffusion flames issuing from two rectangular nozzles were investigated theoretically. Chemical equilibrium model and Zeldovich mechanism were used in numerical model. The effect of four major parameters on NO production were inspected. These parameters are nozzle spacing, Raynolds number, aspect ratio of nozle cross section and velocity of secondary flow. It is found that interaction of flames enhances production of n. It is also found that multiflames with large spacing, small aspect ratio and strong secondary flow product less n.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.37-39
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• 2000

오존에 대한 예보 모델을 연구하는 데는 오존의 생성과 소멸에 관한 광 화학 반응에 대한 이해가 중요한 데 대류권에서 일어나는 알짜 오존 생성(net ozone production)반응은 다음과 같다. (R1) $HO_2$.+NO$\longrightarrow$$NO_2$+OH. (R2) $RO_2$.+NO$\longrightarrow$$NO_2$+RO. (R3) $NO_2$+hu(424< nm) $\longrightarrow$NO+O($^{3}P$) (R4) O($^{3}P$)+$O_2$+M$\longrightarrow$$O_3$+M이때 (R1)과 (R2) 반응에 참여하는 $HO_2$.라디칼 / $RO_2$.라디칼은 주로 대기 중에 존재하는 탄화수소(RH)와 OH.의 반응에 의하여 직접 생성되기도 하고, 이때 생성된 알데하이드(RCHO) 화합물이 OH.과의 반응과 광분해 반응을 통해서 형성된다. 한편, 대도시 지역의 경우 자동차의 배기가스가 알데하이드 화합물의 주요 인위적인 배출원으로 알려져 있다(Viskari et al., 2000, Granby et al., 1997). (중략)

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.185-185
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• 1996

Nitric oxide synthase(NO Synthase:E.C.1.14.13.39)는 생체내에서 L-arginine을 기질로 하여 citrulline과 nitric oxide(NO)를 생성하는 효소로서, 최근 연구에 의하면 2/3 부분 간 절제술 후 prereplicative phase동안에 발현되는 것으로 알려져 있다. 한편, 생체내에서 NO Synthase에 상경적 길항제인 methylarginine에 관해서도 수년간 많은 연구가 진행되어 왔다. 이들의 생성 기전은 protein methylation에 의해 생성된 methylated protein이 생체 내에서 분해되어 생성된다고 알려져 있으나, 정확한 기전에 대해서는 아직 논란의 여지가 많다. 따라서, 본 연구에서는 In vivo 실험을 통해 부분 간 절제술 후 시간대별로 간 조직에서의 NO Synthase 활성도와 혈청에서 NO의 최종 대사물인 Nitrite/Nitrate를 측정하였으며, 또한 NO Synthase 조절에 관여하는 세포내 기질인 arginine과 억제 인자인 methylarginine함량을 간 조직 및 혈청에서 측정하고, 세포 신호 전달체계에 관여하는 cyclic GMP 함량을 측정함으로써, 부분 간 절제술 후 간 재생동안에 NO Synthase 활성도와 methylarginine 및 arginine과의 상관 관계를 규명하고, 간 재생동안, 생성된 nitric oxide의 역할을 연구하려한다.

• Biomedical Science Letters
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• v.5 no.1
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• pp.85-93
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• 1999

Nitric oxide (NO) plays an important role in immunologic defense, and influences upon the functioning of secretory tissues and cells. It also exhibits cytotoxic/cytostatic activity as one of major operating effectors of the cellular immunity system. We investigated the effects of serum on the cell damages and NO production in the mouse liver cell line BNL CL.2 to establish the role of NO. We observed that, when BNL CL.2 cells were cultured in serum-free medium, they were induced to cell damage by the stimulation of IFN-$\gamma$ alone or IFN-$\gamma$ plus LPS. Serum-starved cells showed large amount of nitrite accumulation and NO synthase (NOS) expression in response to IFN-$\gamma$ alone in dose- and time- dependent manners, but serum-supplied cells did not The production of NO was blocked by protein tyrosine kinase (PTK) inhibitors, genistein and herbimycin. These results suggest that the deprivation of serum in the BNL CL.2 cell culture medium might primed with the cells to produce NO when the cells are triggered by IFN-$\gamma$ and the involvement of PTK signal transduction pathway in the expression of NOS gene in murine hepatocytes.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.151-151
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• 1993

A. 1. 중추신경계에서 일어나는 병변들, Alzheimer's disease, Parkinsonism 및 정상적인 노화현상들을 구명하는 연구의 일부분으로 뇌내의 신경세포들의 세포내물질의 변화를 관찰하고자, 이 실험을 시도하였다. 2. 중추신경계에 작용하는 각종 약물들의 작용기전, 그리고 부작용을 구명하여 그의 예방 및 치료방법을 모색하고자 한다. B. 1.Preparations: rat brain cytosol ＆ culture cell-line(NIE-115) 2. Method: NO or NOS의 생성함량을 직접측정 할 수 없으므로 간접방법을 택한다. [3Hlarginine 및 [3Hlguanine을 Preparation에 incubation시켜 일정한 시간 후 생성되는 [3H]citrulline 또는 cyclic GMP을 scintillation counter로 측정하여 그 함량으로 NO or NOS의 생성을 측정한다.

• Journal of Life Science
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• v.18 no.11
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• pp.1471-1478
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• 2008

In this study, nitric oxide (NO) production in a macrophage-lymphocyte co-culture system was used to assess the cytokine producing capability of cells during endotoxin tolerance in mice. Incubation of peritoneal macrophages with interferon-$\tau$ (IFN-$\tau$) in the presence of lipopolysaccharide (LPS) augmented NO synthesis. Exogenous tumor necrosis factor-$\alpha$(TNF-$\alpha$) could also replace LPS for the stimulation of NO production. Macrophages co-cultured with splenic lymphocytes showed augmented NO synthesis by LPS alone. However, pretreatment of mice with 2.5 mg/kg LPS completely prevented the lethality and the increase of blood TNF-$\alpha$ and IFN-$\tau$ after the second challenge with a lethal dose of LPS. In addition, when macrophages prepared from LPS-tolerant mice were co-cultured with normal splenocytes, LPS also could not induce the production of NO, even in the presence of exogenous TNF-$\alpha$. Moreover, when normal macrophages were co-cultured with splenocytes obtained from LPS-tolerant mice, stimulation with LPS could not evoke the NO production enhancement. However, this down-regulation was able to reverse by exogenous IFN-$\tau$ or concanavalin A (ConA), a stimulator of IFN-$\tau$ production. Our results indicate that not only macrophages but also lymphocytes contribute to LPS tolerance. As INF-$\tau$ can enhance the expression of TNF-$\alpha$, the decrease of INF-$\tau$synthesis from lymphocytes may orchestrate with the decrease of TNF-$\alpha$ synthesis from LPS-tolerant macrophages for the production of tolerant state and the prevention of excessive inflammation. Therefore, LPS tolerance may be exploited for prophylaxis of severe sepsis in patients at risk.